EFFECTS OF HIGH CARBON DIOXIDE LEVEL ON THE EMERGENCE OF OIL PALM POLLINATING WEEVIL, Elaeidobius kamerunicus

Elaeidobius kamerunicus is the main pollinating insect of oil palm in Malaysia. The increase of ambient carbon dioxide (CO2) may promote greater crop growth and yield of oil palm. However, E. kamerunicus’ adaptability and survival under high CO2 level are still unknown. An oil palm weevil emergence study was conducted in plant growth chambers with two CO2 levels, 400 ppm and 800 ppm. The plant growth chambers were set at 27°C and 70% relative humidity for the entire study period. Spikelets were taken from apical, middle and basal regions of anthesising male inflorescences from 6-year old DxP palms under normal field conditions. The sampled spikelets were placed in clear plastic tubes with both open ends covered with muslin cloth. The emergence of adults was observed at two-day interval until 10 days after incubation. The total number of weevils which emerged from the spikelets at 400 ppm and 800 ppm CO2 levels were 240 and 233 individuals, respectively. Doubling the ambient CO2 level to 800 ppm had no effect on E. kamerunicus emergence in controlled condition. Further study on oil palm weevil adaptability and survival under high CO2 level is needed to provide information on the effects of future climate change scenario and oil palm yield.